Pans, rivers and artificial waterholes in the protected areas of the South-Western Kalahari

Current knowledge of pans, rivers and artificial waterholes in the three adjoining protected areas of the south-western Kalahari is synthesized and their ecological components are examined in relation to the overall Kalahari ecosystem. Although the pans and rivers are normally dry they have many features not found in the sandveld, and so form important subsystems in the overall ecosystem. The main differ-\udence between the pan and river ecosystems is their drainage, which is endorheic and open respectively. This difference necessitates different conservation strategies for the two systems. Self-maintenance and selfregulation in the pan ecosystem is discussed and it is shown how the combined interactions of the biotic and abiotic components are essential for these processes. Artificial waterholes are not an essential source of moisture for Kalahari fauna but may play a role in stabilizing or concentrating certain populations. When waterholes are highly mineralized they also provide an additional source of minerals for the fauna. The ecological significance of pans, rivers and artificial waterholes in the Kalahari ecosystem needs further investigation